Cold tolerance of insects and other arthropods

Arthropods, as poikilotherms, adapt to cold environments in a variety of ways that include extension of locomotory activity to low temperatures, enhancement of metabolic rate and maintenance of a positive energy balance whenever possible. The ecological implications for many such animals are extension of the life cycle and a requirement for an individual to overwinter several times. Prolonged sub-zero temperatures increase the risk of tissue freezing, and two main strategies have been evolved, first avoidance of freezing by supercooling, and secondly, tolerance of extracellular ice. In the first strategy, freezing is invariably lethal and extensive supercooling (to — 30 °C and below) occurs through elimination or masking of potential ice nucleators in the body and accumulation of cryoprotective substances such as polyhydric alcohols and sugars. Such species are termed freezing intolerant. The second strategy, freezing tolerance, is uncommon in arthropods and other invertebrates, and usually occurs in a single life stage of a species. Freezing of liquid in the extracellular compartment is promoted by proteinaceous ice nucleators. Freezing is therefore protective, and the lethal temperature is well below the supercooling point in freezing tolerant individuals, whereas in most freezing intolerant species it is close to or at the supercooling point. Proteins also act as antifreezes in insects of both strategies, producing a thermal hysteresis by lowering the freezing point of haemolymph in a non-colligative fashion while not affecting the melting point temperature. Recent studies and developments in arthropod cold tolerance are discussed against this background, and a broader approach than hitherto is advocated, which integrates ecological information with physiological data.

2020 ◽  
Vol 113 (3) ◽  
pp. 1254-1261
Author(s):  
Jiahe Pei ◽  
Chengcheng Li ◽  
Lili Ren ◽  
Shixiang Zong

Abstract Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) is a woodboring pest that severely damages urban and plain afforestation trees in northern China. Cold hardiness is an important strategy for the insect to survived during low winter temperatures. Understanding the strategy of S. insularis might provide insights for pest management approaches. To assess the key factors affecting cold hardiness, we measured the supercooling point, freezing point, total water content, total fat content, glycogen content, and total protein content of overwintering larvae. The relationships between supercooling points, temperature, body size, and nutrients were analyzed. The results showed that the supercooling point and freezing point of the larvae decreased first, reached the lowest point in January, and then increased during the rest of the overwintering period. The supercooling point positively correlated with the daily average temperature and the daily minimum temperature. Total lipid content negatively correlated with the supercooling point, while glycogen content had a significant positive correlation with the supercooling point. The temperature may have a major impact on cold hardiness, whereas individual body size may have no significant influence over cold tolerance. During the overwintering process, glycogen and total lipid contents may directly affect cold hardiness. Therefore, the lipid and carbohydrate metabolism may play a role in the cold tolerance of S. insularis larvae. This study provides a physiological and biochemical basis for future metabolic studies on S. insularis larva and the research of overwintering strategies.


1973 ◽  
Vol 51 (1) ◽  
pp. 61-63
Author(s):  
Ajai Mansingh

After 3 weeks of chilling at 4 °C, last-instar larvae of the wax moth G. mellonella required about 40 min at 25 °C to regain posture and locomotory activity; 65% of the larvae died subsequently. Topical application of 2 μl FME significantly reduced the "recovery time" and enabled 75% of the treated larvae to survive the cold exposure.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 144 ◽  
Author(s):  
Tomáš Ditrich ◽  
Václav Janda ◽  
Hana Vaněčková ◽  
David Doležel

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.


2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Glady I. Rambert

Abstract: Water distribution in each compartment of the body involves concentration of solutes in body fluids, and the amount of dissolved substance in a solvent called osmolality. Electrolyte that has the biggest contributor in determining the serum osmolality is sodium, which is osmotically active. Hipoosmolality actually describes the state of hyponatremia, and hyperosmolality describes the state of hypernatremia. Examination of plasma and urine osmolality is very helpful in the management of patients with water and electrolyte imbalance, in addition to assess the antidiuretic hormone (ADH) abnormalities. Urine osmolality is important in evaluating the ability of the kidney to concentrate the urine, in addition to monitor the fluid and electrolyte balance. There are two ways of osmolality examination: 1) indirectly, by using osmometer (osmolality measurement) with a freezing point depression method; 2) directly, by using a formula (osmolality count).Keywords: water, sodium, osmolality, freezing point depression, osmolality countAbstrak: Distribusi air pada setiap kompartemen tubuh melibatkan kadar zat terlarut di dalam cairan tubuh, dan jumlah zat terlarut dalam suatu pelarut yang disebut osmolalitas. Elektrolit pemberi kontribusi terbesar dalam menentukan besarnya osmolalitas serum ialah natrium, yang aktif secara osmotik. Keadaan hipoosmolalitas sebenarnya menggambarkan keadaan hiponatremia, sebaliknya hiperosmolalitas menggambarkan keadaan hipernatremia. Pemeriksaan osmolalitas plasma dan urin sangat membantu penatalaksanaan pasien dengan gangguan keseimbangan air dan elektrolit, selain menilai kelainan antidiuretic hormone (ADH). Osmolalitas urin penting untuk mengetahui kemampuan ginjal memekatkan urin, selain memonitor keseimbangan cairan dan elektrolit. Terdapat dua cara pemeriksaan osmolalitas yaitu: 1) secara tidak langsung menggunakan osmometer (osmolalitas ukur) dengan metode freezing point depression; 2) secara langsung dengan menggunakan rumus (osmolalitas hitung).Kata kunci: air, natrium, osmolalitas, freezing point depression, osmolalitas hitung


2020 ◽  
Author(s):  
Sonya Geange ◽  
Pieter Arnold ◽  
Alexandra Catling ◽  
Onoriode Coast ◽  
Alicia Cook ◽  
...  

<p>Extreme temperature events are increasing in frequency and intensity across the globe. These extremes, rather than averages, drive species evolution and determine survival by profoundly changing the structure and fluidity of cell membranes, altering enzyme function, and denaturing proteins. Given not only our dependence on agricultural crops and natural vegetation, but also the role of photosynthetic processes within the carbon and hydrological cycles, it is imperative to assess the state of our understanding of the potential impacts of extreme events on plants. Scaling responses from the molecular and organ level to ecosystem function is not without challenge however. There is vast literature on plant thermal tolerance research, but the body of literature is so large, the approaches so disparate and often siloed among disciplines, that research in this field risks floundering at a critical time. We conducted a systematic review of more than 21,500 studies spanning over 100 years of research that yielded almost 1,700 included studies on the tolerance of cultivated and wild land plants to both heat and cold. Our review indicates that most studies on thermal tolerance focus on the cold tolerance of cultivated species (52%) and only a trivial percentage of studies have considered both heat and cold tolerance of any given species (~5%). Combined heat and cold tolerance are important in areas where plants are exposed to extremes of both or may be in the future. This review illustrates the global distribution and concentrations of thermal tolerance studies and the diversity of thermal tolerance methods, ranging from molecular to biochemical, physiological and physical examinations, from transgenic model plants to agricultural and horticultural crops, to natural forest trees, shrubs, and grassland herbs. Critically, it also demonstrates that methods and metrics for assessing thermal tolerance are far from standardised, such that our potential to achieve mechanistic insight and compare across species and biomes is compromised. Without reconciling these issues, the scope for incorporating this critical ecological information into vegetation elements of land surface models may be limited. To aid this, we identify priorities for achieving efficient, reliable, and repeatable research across the spectrum of plant thermal tolerance. These priorities, including meta-analytical approaches and comparative experimental work, will not only further fundamental plant science, but will prove essential next steps if we are to integrate such diverse data on a critical plant functional trait into a usable metric within biogeochemical models.</p>


2004 ◽  
Vol 39 (4) ◽  
pp. 525-536 ◽  
Author(s):  
Brian J. Cabrera ◽  
Shripat T. Kamble

Supercooling points were determined for untreated field-collected and untreated laboratory-maintained Reticulitermes flavipes (Kollar) workers and soldiers. Workers treated with antibiotics or had their hindgut-protozoa removed by exposing them to oxygen under pressure to determine the effects of absence of the hindgut fauna on supercooling. Supercooling points were compared between live and freshly-killed workers to determine whether supercooling in this species might be simply due to the biochemical properties of body fluids. Laboratory-maintained workers were also subjected to desiccation, starvation, or atmospheric pressure to determine their effects on supercooling. Supercooling points were lowest for laboratory workers treated with antibiotics and those that fed on brown paper-toweling for 7 d. Untreated field-collected workers had significantly higher supercooling points than untreated laboratory-maintained workers (−6.06 ± 0.79°C vs −9.29 ± 2.38°C, P < 0.0001). Both untreated field-collected and laboratory soldiers had significantly lower supercooling points than their respective workers (−7.39 ± 2.01°C vs −6.06 ± 0.79°C, P < 0.0001; and −11.60 ± 2.53°C vs −9.29 ± 2.38°C, P< 0.0001, respectively). There was no significant association between termite body mass and supercooling points for both laboratory and field termites (P= 0.0523 and P = 0.6242) or water content of laboratory termites and supercooling points (P = 0.1425). Defaunated workers had significantly lower supercooling points (−10.34 ± 2.38°C) than normally faunated workers (−9.48 ± 1.85°C)(P= 0.0095) suggesting that the symbiotic fauna may have higher supercooling points and act as ice nucleators in the termite hindgut. Starved and desiccated workers had significantly lower supercooling points (−10.38 ± 2.70°C and −10.39 ± 2.38°C, respectively) than their corresponding control groups (−9.87 ± 2.11°C and −9.89 ± 1.94°C; P = 0.0454; P = 0.0234, respectively) and untreated workers (−9.29 ± 2.38°C; P= 0.0021; P= 0.0011) suggesting that some forms of physical stress might lower the supercooling point.


2021 ◽  
Vol 11 (3) ◽  
pp. 48-58
Author(s):  
Michael S Rahman ◽  
George P Einstein ◽  
Orien Tulp

White Adipose Tissue (WAT) is typically regarded as a passive storage deposit of excess fat. However, recent research suggests that WAT behaves like an organ system that interacts with the autonomous nervous, endocrinological and immunological systems. Therefore, it is possible that WAT acts as a regulatory organ that keeps the body in homeostasis. This cross-sectional study uses physiological data from 30 patients at the Pinewood Natural Health Centre in Toronto, Canada to derive a description of the role of WAT in the mediation of homeostasis. Statistical methods derive a formula describing the dynamic congruence that contributes to a systems medicine (SM) understanding of the organism. Multiple variables including body parameters, composition, and metabolism, heart rate variability and the immune, autonomous, neural, and endocrinologicial systems were measured and correlated using multiple regression analysis. The null hypothesis was that no variables would correlate; the alternative hypothesis was that at least two variables that would correlate with each other to demonstrate congruence and order. This analysis found strong correlations with parameters of the immune system and metabolism and few correlations with the autonomous nervous system. This suggests that despite the body’s complexity, not all systems may contribute equally strongly to overall homeostasis


1991 ◽  
Vol 69 (12) ◽  
pp. 3028-3037 ◽  
Author(s):  
Olga Kukal ◽  
Matthew P. Ayres ◽  
J. Mark Scriber

A steep decline in the diversity of swallowtail butterfly species at high latitudes could be due to limited cold tolerance of overwintering pupae. If this is so, species with unusually northerly distributions should be unusually cold tolerant. We compared the northerly distributed Papilio canadensis with its southern relative, P. glaucus. Pupae were exposed for 2–5 months to four acclimatization treatments: outdoors in Alaska, outdoors in Michigan, constant 5 °C, and constant −25 °C. Field temperatures encountered by pupae in Alaska were lower than in Michigan. The supercooling point of P. glaucus pupae was unaffected by acclimatization (mean ± SE= −23.5 ± 0.52 °C). The supercooling point of P. canadensis pupae did not differ from that of P. glaucus pupae, except following acclimatization in Alaska, when it dropped to −27.0 ± 0.55 °C. Survival of pupae in Michigan was high for all populations (70–90%); in Alaska, survival of P. canadensis was just as high, but survival of P. glaucus dropped to 14%. Freezing was usually fatal in both species, but death was not immediate. No pupae survived 6 weeks at −25 °C. Trehalose was the most conspicuous metabolite revealed by nuclear magnetic resonance spectroscopy of live pupae and hemolymph. Labelled glucose was metabolized differently by the two species, which may underly the difference in acclimation potential and cold tolerance. The results support the hypothesis that winter temperatures limit swallowtail distributions.


2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Muhammad Syafiq Noor Azizi ◽  
Azahari Salleh ◽  
Adib Othman ◽  
Nor Azlan Mohd Aris ◽  
Najmiah Radiah Mohamad

In modern telemedicine systems the physiological data of patients can be measured with the aid of electronic sensors located on and inside the human body. The collected medical data is then transmitted wirelessly to an external unit for processing, thereby enhancing the health monitoring, diagnosis, and therapy of the patients. In biomedical application, the process requires transmitting data, images and videos from inside the body taken by a radio system of a size of a pill seems to be the way. The use of non-ionizing electromagnetic radiation in various areas like medical application has arisen the electromagnetic radiation problem. The services provided by this type of application can cause either good or bad effects on human body depending on the power level, frequency and the way it being used. The implant antenna with ultra-wideband (UWB) frequency will be used by inserting it into the nerve of human arm in term of homogenous model. Ultra-wideband (UWB) is a wireless technology that potential applications in variety of medical areas such as implant wireless sensors, microwave hyperthermia, imaging and radar. It can transmit digital data over a wide frequency spectrum with very low power and at very high data rates. Hence, this paper present the non-ionizing electromagnetic radiation effect on electrical nerve fiber of human arm model with the presence of other human tissues such as fat, muscle, skin and etc. at ultra-wideband frequency which is expected to improve the understanding of radio propagation inside human body hence contribute to more advance and innovative medical implants. CST Microwave Studio is one of the EM modeling code which can be used for bio electromagnetic purpose.


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